橡胶冷喂料挤出过程轴向温度分布

对橡胶冷喂料挤出过程轴向温度分布进行了实验及理论分析。计算并测定了螺杆轴向湿度分布,确定了胶料沿螺杆轴向的温度变化规律,提出了橡胶冷喂料挤出不同于塑料挤出熔融过程的粘流转变概念。     

橡胶冷喂料挤出机螺杆参数与生产能力实用数学模型的初步研究

运用正交回归试验方法，在φ６５橡胶冷喂料挤出机实验台上，研究了螺杆主要参数（长径比，螺旋升角，螺槽深度，螺杆几何压缩比）及主要挤出工艺、物性参数（螺杆转速，机头口型，胶料种类）对橡胶冷喂料挤出机生产能力的影响。对各实验因素及实验结果做了统计分析，确定了上述各因素对冷喂料挤出机生产能力影响的显著因素，得出了生产能力与螺杆及工艺、物性参数之间的定量计算数学模型。     

橡胶冷喂料挤出机螺杆参数与消耗功率实用数学模型的研究

运用正交回归试验方法，在φ６５橡胶冷喂料挤出机实验台上，研究了螺杆主要参数（长径比、螺旋升角、螺槽深度、螺杆几何压缩比）及主要挤出工艺、物性参数（螺杆转速、机头口型、胶料种类）对橡胶冷喂料挤出机消耗功率的影响。对各实验因素及实验结果做了统计分析，确定了上述各因素对冷喂料挤出机消耗功率的影响，建立了消耗功率与螺杆及工艺、物性参数之间的定量计算数学模型。     

橡胶挤出设备与工艺的发展趋势

综述了 3 0年来橡胶挤出设备与工艺的发展趋势 ,包括设计上的重大改进及挤出工艺上的相应变化。讨论了挤出工艺条件对挤出能力的影响 ,并对热喂料、冷喂料、抽真空冷喂料三代挤出机从技术经济角度进行了综合比较     

橡胶冷喂料挤出机螺杆参数与机头压力实用数学模型的研究

运用正交回归试验方法，在Φ橡胶冷喂料挤出机实验台上，研究了螺杆主要参数（长径比，螺旋角，螺槽深度，螺杆几何压缩比）及主要挤出工艺、物性参数（螺杆转速、机头口型，胶料种类）对橡胶冷喂料挤出机机头压力的影响。对各实验因素及实验结果做了统计分析，确定了上述各因素对冷喂挤出机机头压力影响的显著因素，得出了机头压力与螺杆及工艺、物性参数之间的定量计算数学模型。     

橡胶冷喂料挤出机螺杆参数与消耗功率实用数学模型的研究

运用正交回归试验方法，在φ６５橡胶冷喂料挤出机实验台上，研究了螺杆主要参数及主要挤出工艺、物性参数对橡胶冷喂料挤出机能耗功的影响。     

摩擦因素对橡胶冷喂料挤出固体输送率的影响

对橡胶冷喂料挤出过程喂料段固体输送率(Q)的影响因素进行了理论分析及实验研究,讨论了喂料段机筒温度(Tb)、螺杆转速(n)和胶料物理性能对摩擦系数(f)及Q的影响,预测了喂料段长度,综合分析了摩擦因素与胶料性能对喂料效率的作用。结果表明：Tb对冷喂料挤出的胶料与筒壁的摩擦系数有一定影响,Tb最佳值为40～50℃。红管胶与垫带胶的邵尔A型硬度较高,容易在喂料口打滑,对Q有影响。拉伸强度较小的红管胶,不易形成喂料返胶,但容易形成饥饿喂料。拉伸强度较大的普通内胎胶及胎面胶,在螺杆喂料段输送能力较低时,能形成喂料返胶。     

我国橡胶挤出机发展概况

简要介绍了橡胶挤出机的发展情况。对销钉冷喂料挤出机的挤出质量、能源消耗进行了分析，阐述了销钉冷喂料挤出机的优点及普及情况。对复合挤出机的现状及发展进行了简述。针对当前橡胶生产技术的发展和市场需求，指出了销钉式冷喂料挤出机的发展前景。     

橡胶冷喂料挤出过程轴向压力分布

对橡胶冷喂料挤出过程轴向压力分布进行了实验研究及理论分析，以实验数据为基础，拟合出了轴向压力分布函数，并分析了喂料段饥饿喂料与喂料返胶的主要成因，结果表明，轴向压力基本是按指数分布的；胶料的邵尔A型硬度、粘度及拉伸强度不但影响螺槽内压力的大小，也是饥饿喂料及喂料返胶的重要因素；轴向压力波动与螺杆的几何结构变化有关。     

橡胶工业热水循环温控技术使用效果

介绍热水循环温控技术在橡胶密炼机和冷喂料挤出机中的使用效果,指出使用循环热水控温的密炼机可降低耗水量、缩短混炼时间并降低能量单耗;在冷喂料挤出过程中,提高温控系统水温到一定值在提高挤出速度的同时还可提高产品质量,喂料段温度升高对挤出温度影响不显著,但过高的温控系统水温反而会降低挤出速度。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。